In recent years, there has been a tendency to use aluminum wire as a wire routed in an automobile instead of the commonly used copper wire, aluminum wire having the advantages of being lightweight and low-cost. The aluminum wire includes aluminum-based metal strands twisted into a core wire, which is coated by an insulating coating configured by an insulating resin. Meanwhile, a terminal is connected to the wire in order to electrically connect to a busbar, terminal, grounding vehicle body panel, or the like configured by a conductive metal material. The terminal is formed by a copper-based metal due to the copper-based metal having good conductivity and highly reliable electrical connection.
Accordingly, the aluminum-based metal core wire (hereafter referred to as an aluminum core wire) of the aluminum wire is brought into contact with and connected to a copper-based metal terminal. However, when the aluminum core wire and the copper-based terminal are brought into contact, contact is established between the dissimilar metals Al and Cu. Contact between these dissimilar metals increases the likelihood of corrosion, and the advance of corrosion is particularly facilitated when an area of contact between the dissimilar metals is subjected to a snow melting agent, battery electrolyte, rainwater, and wash water.
In response to the above-noted issue, an aluminum wire terminal 100 shown in FIG. 7 has been proposed in Japanese Patent Laid-open Publication No. 2013-20862. In the terminal 100, a surface of a copper-based metal terminal is covered by an aluminum layer, and when core wire barrels 101 of the terminal 100 are swaged and crimped onto an aluminum core wire of an aluminum wire and the aluminum wire and terminal 100 are brought into contact, contact is established between similar metals, preventing corrosion from occurring.